Fact Check: 100% USA Solar

Calculations

# Let's use numbox to check a real life example

# === start of Elons posts ===

# https://x.com/elonmusk/status/1839439841337225277
# "Once you understand Kardashev Scale, it becomes utterly obvious that essentially 
#  all energy generation will be solar. 
#  Also, just do the math on solar on Earth and you soon figure out that
#  a relatively small corner of Texas or New Mexico can easily serve all US electricity."

# https://x.com/elonmusk/status/1839441480114376859
# "One square mile on the surface receives ~2.5 Gigawatts of solar energy."

# https://www.architecturaldigest.com/reviews/solar/how-much-power-does-a-solar-panel-produce#:~:text=Solar%20panels%20are%20rated%20by,kilowatts%20(kW)%20of%20power.
# solar energy:
wattsPerSquareMeter = 1000 W / m ^ 2
wattsPerSquareMile = (wattsPerSquareMeter to W / mile ^ 2) to GW / mile ^ 2

# "(That’s Gigawatts with a “G”. It’s ~30% higher in space.)"
# "(The Starlink global satellite network is entirely solar/battery powered.)"

# "Factoring in solar panel efficiency (25%)," 
afterEfficiencyLosses = wattsPerSquareMile * 25%

# "packing density (80%)"
afterPackingLosses = afterEfficiencyLosses * 80%

# "and usable daylight hours (~6), 
# a reasonable rule of thumb is 3GWh of energy per square mile per day." (is correct)
afterPackingLosses * 6 h to GWh / mile ^ 2
averageWhPerDayPerKmSquared = afterPackingLosses * 6 h to GWh / km ^ 2
averageWhPerDayPerMileSquared = averageWhPerDayPerKmSquared to GWh / miles ^ 2

# "Easy math, but almost no one does these basic calculations."
# === end of Elons post ===


# so lets calculate further:
# https://www.reuters.com/business/energy/us-power-use-forecast-reach-record-highs-2024-2025-eia-says-2024-07-09/#:~:text=EIA%20projected%20power%20demand%20will,4%2C067%20billion%20kWh%20in%202022. 
usaElectricityConsumption2024 = 4.123e+9 kWh

# how many square miles needed for the USA
neededSquareMiles = usaElectricityConsumption2024 / averageWhPerDayPerMileSquared to miles ^ 2

# USA area in miles^2: https://data.census.gov/profile?g=010XX00US
usaSm = 3.809525e+6 miles ^ 2

# this is how much area as a percentage is needed
percentageOfLandNeeded = neededSquareMiles / usaSm / 100

# In conclusion his calcuations are correct and the land needed is as tiny as he said. 
# Far less than one percent.